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90-Degree Projection Cabinets?


The Bear Jew

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OK, perhaps some of you have seen 90-degree projection cabinets before... like this one:

http://i8.photobucket.com/albums/a8/TheGrooveking/SunnBetaLeadand610L.jpg

 

The above pic is NOT of my gear--I'm just posting the image to give an example so that we all know what I'm talking about here.

 

My question is... what is the purpose of the 90-degree baffle? I gather that this kind of construction allows the cabinet to be more narrow... but, beyond this, I don't know what it's supposed to do in a sonic sense.

 

Thoughts?

 

 

\m/

Erik

"To fight and conquer in all your battles is not supreme excellence; supreme excellence consists of breaking the enemy's resistance without fighting."

--Sun Tzu

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That is a guitar amp and cabinet.

 

I would not guess that it had anything to do with anything other than size. The combo amp has 2 speakers in the same configuration.

 

In a real horn cabinet design, I'd expect a 'horn' to be bigger, and probably the opposite co-entrant drivers to be out of phase with each other. Also, that design really restricts the volume of the box. There could be a port behind the logo strip on top of the box, I'm not sure.

 

I remember looking at this amp in the 70s or 80s, I think that this design was just Sunn trying to be eye-catching, as they often were. Some more exotic cabs were released by Richenbacher, which were asymetrical.

 

Anyway, with no better info to go by, I think it was for looks.

"I believe that entertainment can aspire to be art, and can become art, but if you set out to make art you're an idiot."

 

Steve Martin

 

Show business: we're all here because we're not all there.

 

 

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Yes, I know it's a guitar amp and cabinet. My question isn't specific to bass gear--I just know that some of my bass-playing friends here know a good bit about cabinet design, so I thought I'd post it here.

 

After poking around a little more, I have discovered this information from a small cabinet manufacturer who makes 6x12 cabs with the same sort of 90-degree baffle design:

 

"The advantage of the v-type horn is the coupling of the sound waves of drivers to increase sound pressure level, it produces a more impacting tone, which equals tight and LOUD.

 

You get more speakers in a smaller box but you can lose internal volume in the cabinet, that, depending on the speaker used, might not get the most out of each speaker (a loss in efficiency/frequency response)."

 

So, looks like I found the answer on my own. Yay.

 

 

\m/

Erik

"To fight and conquer in all your battles is not supreme excellence; supreme excellence consists of breaking the enemy's resistance without fighting."

--Sun Tzu

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...also...

 

I'd imagine it would create wacky combing effects so if you were walking around in the audience the guitar would probably sound significantly different depending on where you stood. Hard to get the sound in your head if it sounds different everywhere in the room.

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Yeah, after reading more about this design, I've decided I don't want a 90-degree baffled cabinet. I don't even think they look all that interesting.

\m/

Erik

"To fight and conquer in all your battles is not supreme excellence; supreme excellence consists of breaking the enemy's resistance without fighting."

--Sun Tzu

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"The advantage of the v-type horn is the coupling of the sound waves of drivers to increase sound pressure level, it produces a more impacting tone, which equals tight and LOUD.

 

You get more speakers in a smaller box but you can lose internal volume in the cabinet, that, depending on the speaker used, might not get the most out of each speaker (a loss in efficiency/frequency response)."

 

 

The theory is correct, but I question the application.

"I believe that entertainment can aspire to be art, and can become art, but if you set out to make art you're an idiot."

 

Steve Martin

 

Show business: we're all here because we're not all there.

 

 

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What about the Community dual 18" sub that employs this design?

 

Data Sheet

 

I've heard them before and they sound pretty good. Don't know why you would use this design for a subwoofer. I would think you'd have more to gain by taking advantage of the extra enclosure volume to extend response.

Dan

 

Acoustic/Electric stringed instruments ranging from 4 to 230 strings, hammered, picked, fingered, slapped, and plucked. Analog and Digital Electronic instruments, reeds, and throat/mouth.

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C'mon. Be brave. Click on the link I posted above. Here's a cut-n-paste. Emphasis is mine:

 

This minimizes the center to center spacing of the drivers for reduced combing, and widens high frequency horizontal dispersion by up to 40 degrees compared to a flat baffle.

 

 

Things are just the way they are, and they're only going to get worse.

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I did click the link and read the whole thing. Everything discussed on that page has more to do with guitar speakers and would not apply in a subwoofer application where, if anything, you want to project the sound, and wave lengths are much, much longer so that driver to driver spacing will not cause comb filtering.

Dan

 

Acoustic/Electric stringed instruments ranging from 4 to 230 strings, hammered, picked, fingered, slapped, and plucked. Analog and Digital Electronic instruments, reeds, and throat/mouth.

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I remember seeing stuff like that. I don't think they were all that good as you never see cabs like that anymore.

 

+1, with some reservations. Lack of market response isn't always due to inferior product or design. Sometimes, it just doesn't have "THE LOOK". The fact that it doesn't look like a slant-front Marshall cab probably has as much to do with it's disappearance from the market as it's capabilities do. That was it's competition back in the day...

Always remember that you are unique. Just like everyone else.

 

 

 

 

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I did click the link and read the whole thing. Everything discussed on that page has more to do with guitar speakers and would not apply in a subwoofer application where, if anything, you want to project the sound, and wave lengths are much, much longer so that driver to driver spacing will not cause comb filtering.

 

I was referring to Davio's thoughts that it would increase combing, not decrease it. And although in the low Hz range this is (I guess..) less of an issue, we put out more than just sub range. I'd love a wider dispersion of my sound on stage. Sometimes I step a little left or right, and what I hear changes dramatically. (I don't sit down the entire gig, just 75% if it!!!!!)

Things are just the way they are, and they're only going to get worse.

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At one point in my career I had a 2x15 cabinet on one side of the stage and a 1x18+1x10 cabinet on the other side.

 

There were no problems with dispersion. Some members of the audience ended up pinned to the back wall.

 

AW, YEAH! Now that's bass as it should be! If you aren't causing involuntary bowel movements in at least some of the crowd, it not loud enough!

 

Always remember that you are unique. Just like everyone else.

 

 

 

 

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At one point in my career I had a 2x15 cabinet on one side of the stage and a 1x18+1x10 cabinet on the other side.

 

There were no problems with dispersion. Some members of the audience ended up pinned to the back wall.

 

Oh yeah the good ol' days. Back when I used three 2x15 cabs with three 200 watt amps daisy chained together. No problem with dispersion either.

Lydian mode? The only mode I know has the words "pie ala" in front of it.

http://www.myspace.com/theeldoradosband

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I was referring to Davio's thoughts that it would increase combing, not decrease it. And although in the low Hz range this is (I guess..) less of an issue, we put out more than just sub range. I'd love a wider dispersion of my sound on stage. Sometimes I step a little left or right, and what I hear changes dramatically. (I don't sit down the entire gig, just 75% if it!!!!!)

I'll believe their claims when I see empirical evidence from a non-partial third party. Sounds like they're doing some voodoo. And Eden has a 210 that can hit 30hz @ -2dB...yeah...no.

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I did click the link and read the whole thing. Everything discussed on that page has more to do with guitar speakers and would not apply in a subwoofer application where, if anything, you want to project the sound, and wave lengths are much, much longer so that driver to driver spacing will not cause comb filtering.

 

I was referring to Davio's thoughts that it would increase combing, not decrease it. And although in the low Hz range this is (I guess..) less of an issue, we put out more than just sub range. I'd love a wider dispersion of my sound on stage. Sometimes I step a little left or right, and what I hear changes dramatically. (I don't sit down the entire gig, just 75% if it!!!!!)

 

Yeah, sorry, it sounds like we're kind of talking about 3 different things - first the guitar cabinet listed, second it's application to bass guitar, and third the cabinet I posted which is a large FOH subwoofer.

 

I get the advantage in terms of horizontal coverage for guitar and bass, I don't get the advantage to this arrangement for FOH subs like community uses. Bass in the Subwoofer range is pretty non-directional, and if anything in a FOH application, you would want to focus it - thus the use of scoops and folded horns in larger applications. Also, in subwoofer applications, more enclosure volume = lower cutoff frequency and/or higher efficiency - so stealing volume for this arrangement doesn't seem to make sense in a subwoofer. Am I missing something?

Dan

 

Acoustic/Electric stringed instruments ranging from 4 to 230 strings, hammered, picked, fingered, slapped, and plucked. Analog and Digital Electronic instruments, reeds, and throat/mouth.

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baffle

 

But it's not a baffle...

 

"...... and widens high frequency horizontal dispersion by up to 40 degrees compared to a flat baffle."

 

You're a baffle.

Things are just the way they are, and they're only going to get worse.

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http://wenatchee.craigslist.org/msg/1537303584.html

 

First Guitar for Project B and I are heading to Portland, OR this weekend (maybe, if I'm not working) to pick up a set of mains. He's on my but to pick this up for outdoor gigs. This would be - in fact - 180 degrees if I read the ad right. Despite the fact the ink is still wet on my stimulus money, I'm thinking it will still spend for these. Any thoughts?

 

I'm thinking this is what Erik said earlier taken to it's logical conclusion.

 

Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn

 

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Holy crap! What army will you need to move those things around? You guys have a place to store them? And you're gonna need a bigger car.

 

How many outdoor gigs do you do in a year?

Things are just the way they are, and they're only going to get worse.

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Well, the guy throws in an American Audio VLP 1500 (MF lists at $329.99) for $200 even. Brand new, still in the box.

 

As I told the guitar,

 

"Two 3x15's in an isoberic chamber, $500

One VLP 1500, $200

The ability to kill small mammals and knock down garden sheds at 100 feet ...

 

... priceless!"

 

Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn

 

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What freq is the bandpass tuned for?

 

Subs are tricky for bass.

My thought is you may well lose everything below A.

"He is to music what Stevie Wonder is to photography." getz76

 

I have nothing nice to say so . . .

 

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